Magneto construction.



s. c. McKEOWN. MAGNETO CONSTRUCTION. APPLICATION FILED DEC. 20. I913.

1,249,1 52. Patentd Dec. 4, 1 917. 15' J2 .7; anna H301 I am themes J0 /A UNITED STATES PATENT oF roE.

. SAMUEL CHRISTOPHER MOKEOWN, OF SUMTER,

soucrn CAROLINA, ASSIGNOR, BY

MESNE ASSIGNMENTS, TO SPLITDORF ELECTRICAL COMPANY, OF NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY.

MAGNETO CONSTRUCTION.

To all whom it may concern: Be it known that I, SAMUEL CHRISTOPHER MoKEowN, a citizen of the United States, residing at Sumter, in the county of'Sumter and State of South Carolina, have invented certain new and useful Improvements in Magneto Constructions, of which the following is a specification, reference being had to the accompanying drawing.

My invention relates to magneto construction and has for its object the provision of a magneto of compact construction in which the number of pieces are reduced to a minimum and in which the various parts are rigidly held in operative relation to each other without the use of screws, rivets or othermeans.

A particular feature of my invention is in forming the base plate and rotor housing in one piece, and embedding in thissu'itable pole pieces, which are securelvheld in position by the metal cast around them. This is of great advantage in manufacture, as it enables the cylindrical housing to be more easily and accurately formed and bored out thaai when other methods of assembly are use There are otherobjects of my invention which will be apparent from the following description and the accompanying drawings.

Figure 1 is a perspective view of the casting comprising. the base and rotor housing. Fig. 2, a perspective view of one of the laminated pole pieces adapted to be embedded in the casting shown in Fig. 1. Fig. 3 is a longitudinal cross section of a magneto embodving my invention. Like figures of reference denote the same parts wherever they are shown. The framework consists of a single casting of non-magnetic material such as the alloys commonly employed in die-cast work. This comprises a base plate 1 and a cylindrical housing 2. In the sides of the housing are embedded elongated pole pieces 3 and 4, the inner extremities of which form the circumferential faces 5 and 6 lying substan- Specification of Letters Patent.

ing same ,since they Patented. Dec. 4', 1917.

Application filed Decemher 20, 1913. Serial No. 807,951.

The pins also retain the laminations in registry.

At each end of the base isprovided the extended portion 9 forming a magnet suport. In this is a depression 10. which enables end plates to be-put on the open ends of the cylinder, to which they are attached by means of screws or in any other suitable manner.

While a. one-piece casting as just described may be employed with several types of magnetos, I prefer to make the type shown in crox-section in Fig. 3, in which case I find that it 'is necessary to prevent the circulation of eddy currents about the pole pieces which occurs when they are surrounded with metal. To this end I cut out a portion of the cylinder between the pole pieces as indicated at 11,and find this effectually prevents the circulation of currents around them, as in this type of magneto the current circulates around each pole piece independently. The circulation of these currents may be prevented in other ways, but the removal of some of the metal in proximity to the side of each pole piece will produce the-desired result.

A complete magneto as shown in Fig. 3 is assembled by taking the casting comprising the base and cylindrical housing with its embedded pole pieces, placing across the tops 12 and 13 of said pole pieces the core shown in section at 14 carrying the winding 15, and placing within the cylindrical housing the rotor composed of the shafts 16 and 17, and poles 18 and 19 of magnetic material separated by the non-magnetic block 20.

The rotor structure may be supported on ball bearings indicated at 21 and 22 in the embraced by a permanent magnet, whose polar extremities are indicated at 25 and 26.

I have not deemed it necessary to describe the electrical connections in a magneto of this character, nor the other parts comprisform no part of my invention and are well understood by those skilled in the art. It will be observed however that in a machine of the type shown,

the end plates 23 and 24 really form-extensions of the magnet poles and that the members 18 and 19 of the rotor in turn constitute further extensionsof said magnet poles and always possess the same polarity irrespec- 25 end plates and the projecting ends of the in'g therefrom, magnetic end plates for the housing, fitted with axial bearings to receive the rotor shaft, a core member engaging-the projecting ends of the pole pieces and a magnet having its polar extremities in lateral contact with said-end plates.

2. In a magneto generator, a base, a rotor having a shaft, pole pieces in operative relation to said rotor, and a housing for the rotor composed of cast metal with said pole pieces embedded therein with their ends projecting therefrom, magnetic end plates for said housing, fitted with central bearings for the rotor shaft, a field magnet and a magnetic bridge carrying a generating coil, forming complementary elements for the pole pieces, said magnet extending downwardly to the base and being supported thereby. 1

3. In a magneto generator, a base, a rotor having a shaft, pole pieces in operative relation to said 'rotor, and a housin for the rotor composed of cast metal with said ole 1 pieces embedded therein with their ends projecting therefrom, magnetic end plates for the housing fitted with bearings for the rotor shaft, a field magnet adapted to en gage said end plates and rest upon said base, and a magnetic bridge carrying'a gencrating coil, adapted to engage the projecting ends of the pole pieces.

4. In a magneto generator, a rotor, pole pieces in operative relation to said rotor,

and a housing for the rotor composed of cast metal with said pole pieces embedded therein, said housing having an opening from one pole piece to the other.

5. In a magneto generator, a magnetic field structure, a rotor embraced by said field structure having elements permanently and oppositely polarized thereby, a housing surrounding said elements and embraced by said magnetic field structure, pole piecesembedded in said housing, said housing being disposed in relation to .said pole pieces whereby the circulation of eddy currents L between the pole pieces is prevented, substantially as described.

6. In a magneto generator, a rotor, pole pieces in operative relation to said rotor, a housing for the rotor composed of cast metal with said pole'pieces embedded therein said housing having a metallically discontin"o':s portion between said pole pieces for preventing eddy currents between the pole pieces.

7. In a magneto generator a pair of spaced flux receiving pole shoes with upwardly projecting free parallel members, their inner faces being shaped to permit the operation of an inductor between them, a cast metal base with an upwardly extending integral shell or body having the pole pieces embedded therein and thereby forming a unit structure with said base said shell being constructed to receive the inductor with its axis at right angles to the plane of said pole pieces.

' In testimony whereof I hereunto affix my signature in the presence of twowitnesses.

SKMUEL CHRISTOPHER MCKEOWN. Witnessis'z H. VAN DEVENTER, E. B. Isms. 

